SUMMARY A patient with post-hypoxic myoclonus, sensitive to therapy with 5-hydroxytryptophan and clonazepam, was subjected to detailed electrophysiological investigation. Brief generalised jerks followed the critical stimulus of muscle stretch. The electroencephalogram showed generalised spikes that were associated with, but not time locked to, the myoclonus. The cranial nerve nuclei were activated upward. Analysis of the findings suggests that the mechanism of the myoclonus is hyperactivity of a reflex mediated in the reticular formation of the medulla oblongata.

Averaged visual evoked responses to pattern reversal stimuli have been recorded in 54 control subjects, 51 patients with multiple sclerosis, and 55 patients with other neurological diseases which might involve the visual apparatus. The latency to the peak of the major positive potential in normal subjects under the age of 60 was 104 msec or less (mean 90-5 msec+3 SD). The latency of the VER was prolonged above this value in one or both eyes in 67 per cent of the patients with multiple sclerosis (in 84 per cent of those with definite multiple sclerosis, in 83 per cent of those with probable multiple sclerosis, and in 21 per cent of those with possible multiple sclerosis). The latency of the VER was also prolonged in 25 percent of those with an acute spinal cord lesion of unknown cause; in 46 per cent of those with an isolated brain-stem lesion unknown cause; and in 49 per cent of patients presenting with a progressive spastic paraparesis. The extra delay in latency varied from a few msec to as much as a 100 msec. In patients with multiple sclerosis, a delayed VER was found in the affected eye in all with a previous history of optic neuritis, and in 47 per cent of those with no such history....

Patients taking oral contraceptive steroids (OCS) are known to suffer contraceptive failure while taking anticonvulsants such as phenobarbitone, phenytoin and carbamazepine. We have studied the single dose kinetics of ethinyloestradiol (EE2); 50 ,ug, and levonorgestrel (Ng); 250 p,g in groups of women before and 8-12 weeks after starting therapy with phenytoin (n = 6) and carbamazepine (n = 4). The area under the plasma concentration-time curve (AUC) was measured over a 24 h period for each steroid and significant reductions were seen with both anticonvulsants. Phenytoin reduced the AUC for EE2 from 806 ± 50 (mean ± s.d.) to 411 ± 132 pg ml-' h (P < 0.05) and for Ng from 33.6 ± 7.8 to 19.5 ± 3.8 ng ml-' h (P < 0.05). Carbamazepine reduced the AUC for EE2 from 1163 ± 466 to 672 ± 211 pg ml-' h (P < 0.05) and for Ng from 22.9 ± 9.4 to 13.8 ± 5.8 ng ml-' h (P < 0.05). These changes are compatible with the known enzyme inducing effects of phenytoin and carbamazepine. Patients taking these anticonvulsants will need to be given increased doses of OCS (equivalent to 50-100 ,ug EE2 daily) to achieve adequate contraceptive effects.

No abstract

The authors report a double-blind, placebo-controlled, crossover study of talampanel in 49 patients with refractory partial seizures. Three doses of talampanel were investigated based on differences in patients' concomitant antiepileptic drug usage. Talampanel showed efficacy in reducing seizure frequency (p = 0.001) with a median seizure reduction of 21%. Eighty percent of patients had fewer seizures on talampanel than on placebo. Dizziness (52%) and ataxia (26%) were the only significant adverse events.